Today, people and businesses rely on networked computer systems to support distributed applications. As the number of different networks and applications has grown, the number of specialized directories of information has also grown, resulting in islands of information that are difficult to share and manage. Maintaining and accessing this information in a consistent and controlled manner provides a focal point for integrating a distributed environment into a consistent and seamless system.
The Lightweight Directory Access Protocol (LDAP) is an open industry standard that has evolved to meet these needs. LDAP is based on the client/server model of distributed computing and defines a standard method for accessing and updating information in a directory. In computer terms, a directory is a specialized database, also called a data repository, that stores typed and ordered information about objects. LDAP has gained wide acceptance as the directory access method of the Internet and is therefore also becoming strategic within enterprise intranets. It is being supported by a growing number of software vendors and is being incorporated into a growing number of applications. However, current solutions propagate data and information too frequently, resulting in unnecessarily large databases and data transfers. Existing directory integration methods fetch data before it is requested. A large batch of data is retrieved from the data sources, while the data in the directory is replaced. Any subsequent changes to the sources are also changed in the directory. Because it is not determined which information will be needed in the future by the client, all of the data is propagated.